Wireless networks continue to evolve as new communication technologies develop and standardize. Wireless network operators can deploy new communication technologies in parallel with earlier generation communication technologies, and wireless networks can support multiple communication technologies simultaneously to provide smooth transitions through multiple generations of mobile wireless devices. Mobile wireless devices can include hardware and software to support wireless connections to different types of wireless networks that use different wireless communication technologies. Representative wireless communication technologies include technologies deployed by wireless networks based on communication protocols codified by the Third Generation Partnership Project (3GPP) and the Third Generation Partnership Project 2 (3GPP2) standards bodies. Communication protocols include the 3GPP Universal Mobile Telecommunications System (UMTS) wireless communication protocol, the 3GPP Global System for Mobile Communications (GSM) wireless communication protocol, and the 3GPP Long Term Evolution (LTE) and LTE-Advanced wireless communication protocols. Communication protocols also include the 3GPP2 Code Division Multiple Access (CDMA) 2000 1x (also referred to as 1xRTT or 1x) wireless communication protocol. The teachings provided herein are described in terms of the 3GPP LTE and LTE-Advanced wireless communication protocols but can also apply to mobile wireless devices that operate using other wireless communication protocols.
In some wireless communication protocols, e.g., the 3GPP UMTS wireless communication protocol, a mobile wireless device can detect an extended period of inactivity while connected to a wireless access network. The mobile wireless device can transmit a request to the wireless access network to release a connection between the mobile wireless device and the wireless access network after detecting the extended inactivity period. The mobile wireless device, upon receipt of a response from the wireless access network, can transition from a higher power consumption connected state to a lower power consumption idle state, thereby conserving battery resources of the mobile wireless device. A representative embodiment of this power saving feature is known as “fast dormancy” for the UMTS wireless communication protocol.
The 3GPP LTE and LTE-Advanced wireless communication protocols do not include a mobile wireless device based feature equivalent to the “fast dormancy” provided in the UMTS wireless communication protocol. During an extended period of inactivity, while in a connected mode, the mobile wireless device can continue to consume power at a higher rate, even without any data transmission or reception by the mobile wireless device. Although the wireless access network can detect a period of inactivity and transmit a message to the mobile wireless device releasing a connection with the mobile wireless device, in certain circumstances, the mobile wireless device can miss receiving or not properly decode the connection release message transmitted by the wireless access network. The wireless access network, having sent the connection release message, can consider the mobile wireless device to be in an idle (not connected) state, while the mobile wireless device, having missed the connection release message, can remain in a connected state. In the absence of an inactivity timer at the mobile wireless device or a mechanism to request a transition to an idle state, the mobile wireless device can remain in the higher power connected state for a considerable length of time draining power from its battery. Thus, there exists a need to detect periods of inactivity at the mobile wireless device and adjust connection states of the mobile wireless device, e.g., to transition the mobile wireless device from a high power consumption connected state to a low power consumption idle state.
This application describes methods and apparatuses by which a mobile wireless device can adjust connection states between the mobile wireless device and a wireless network upon detection of a prolonged period of inactivity at the mobile wireless device.